Drill spindle driving mechanism



Sept. 11, 1945. .w. G. HOELSCHER I DRILL SPINDLE DRIVING MECHANISM Filed July 28, 1959 14 Sheets-Sheet l IN VENTOR.

QTTORNEY;

Sept. 11, 1945. w. Gf HOELSCHER 2,384,744

DRILL SPINDLE DRIVING MECHANISM 7 Filed July 28, 1939 "14 Sheets-Sheet 2 l 1945. w. G. HOELSCHER 2,384,744 DRILL SPINDLE DRIVING MECHANISM I Filed July 28, 19:59 14 sheets-sheet s INVENTOR.

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I DRILL SPINDLE DRIVING MECHANISM Filed July 28, 1959 14 Sheets-Sheet 4 I 15 .6 km WM WW6;

' TTORNEY5 w. G. HOELSCHER DRILL SPINDLE DRIVING MECHANISM 14 Sheets-Sheet 5 Filed July 28, 1939 INVENTOR.

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14 Sheets-Sheet 6 P 1945. w. G. HOELSCHER DRILL SPINDLE DRIVING MECHANISM Filed July 28, 1959 WMWMTTORMEY5 Sept. 11, 1945. wfe HCELSCHER 2,384,744

DRILL SPINDLE DRIVING MECHANISM Filed July 28, 1959 l4 Sheets-Sheet 7 //////////////I////////////Il////l//// 2340 V as 7 if A if IIIHI m J I 4' 7 :1 v ij" 51 VENTOR.

F914 WM ATTORNEYS Sept. 11, 1945. w. G. HOELSC-HER I DRILL SPINDLE DRIVING MECHANISM Filed Ju i} 28, 1939 14 Sheets-Sheet 9 W fTTORNEYJ r n I- Sept. 11, 1945.

Filed July 28, 1939 Winnwi F ym z? w. G. HO'ELSCHER I DRILL SPINDLE DRIVING MECHANISM (I. 11111 ll. 'IIII/ '11 111 11/1/1111/1 1/11/11, III/III. v. 7/1114 villi/111 1111111111! 14 Sheets-Sheet 10 INVENTOR.

ATTORNEY.

Sept. 11, 1945. w. G. HOELSCHER 2,384,744

DRILL SPINDLE DRIVING MECHANISM I Filed July 28, I939- I 14 Sheets-Sheet 12 i I l i 1 f Y INVENTOR;

WM ATTOREEYg J Sept. 11, 1945.

W. G. HOELSCHER Filed July 28, 1939 14 Sheets-Sheet l3 450 4H 422 419 I M M Ii 4, I. f

4mm; 456 455 $3 a;

irw 425' 429 45 J 414 .j I 87 6 0 64 0 ,Fyuif 464 4124 a INVENTOR.

Sept. 11, 1945. w. G. HOELSCHERI- 2,384,744

DRILL SPINDLE DRIVING MECHANISM Filed July 28, 1939 14 Sheets-Sheet 14 i F I 404 413 g y .%50 422 4Z5 4Z3" 41 .i arr llllllll 462 'v "m y j INVENTOR.

v WMATTORNEYJ Patented Sept. 11, 1945 sa'rs rarsur DRILL SPEN'DLE DEG ME William G. Hoelscher, Chicinnati, Ohio, assignor to The American Tool Worksilompany, @in cinnati, Ohio, a corporation oi @hio a uca ucnruiias, 1939, Serial ar 287,132,

"11 claims.

This invention relates to machine tools and is particularly directed to radial drills. More specifically, the invention is directed to improvements in the tool spindle operating mechanism. It has been the object of the present inventor to provide an improved arrangement of the power shaft which delivers the power generally to'the drill head of the radial drill; The improvement makes it possible to interchange without diiiiculty the main driving gears, which connect the motor to the head driving shaft. These gears are disposed in a position where they are conveniently accessible and where their removal does not require any substantial disassembly. Accordinglmin the event that the operator desires a general increase or decrease in speed to the head, he ,can quickly remove the component driving gears and replace the same with another set of component gears of the desired ratio.

It has been another object of the present inventor to provide spindle driving and feeding of gears whereby fewer gears are required for a given speed. The structure is more compact and less mechanism is required. A structure accomplishing this result may consist of a single intermediate shaft, effective for increasing speeds from one to four by the use of a cluster of three gears on the intermediate shaft and clusters of two gears each .on the adjacent shafts. One of the adjacent clusters of two gears is shiftable relative to the cluster of three gears to accomplish two speeds, or may be shifted again relative to the cluster of three gears after the cluster of three gears has been moved to a second gear coupling position, thereby accomplishing two more speeds.

It has beena still further object of the inventor to provide an improved feed controlling and transmissions, each shifted by means of a pair of levers for providing the appropriate transmission connections. In each instance, one of the levers of the pair is for shifting between two ranges and the other is for shifting to the specific speeds or feeds within these ranges.

It has been the further object in this arrangement to provide these levers so that they are more conveniently shifted and so that the operator may determine the position of the respective transmissions by means of improved dials, greatly facilitating correct reading. In both transmis-. sions, that is speed and. feed, the dials provide panels having light and dark zones for the re-' spective ranges. When the specific feed or speed control leverv is imposition indicating the speeds within a particular panel, the operator can read- 'ily determine whether or not it is low or high speed by observing the position of the range shifting lever relative to its paneL which includes, as well, the light and dark zones. Thus, it is possible to read the speedsand feeds directly adjacent the levers, for the levers actualh' indicate the feeds or speeds by virtue of the positions of the levers relative to the panels.

It is a further object of the inventor to provide gear shifting means for the transmission of the spindle wherein a number of gears may be shifted from a single cam and wherein the gears shit-t easily and without frictional resistance.

This is accomplished by counterbalancing means associated with each vertically supported gear.

- It has been a still further object of the present inventor to provide an improved arrangement regulating mechanism for the spindle in which will constantly maintain the coupling mechanism in position whereby the clutch is immediately automatically engaged after the adjustable stop 'dog is reset out of feed disconnection position.

Also, the feed setting means is improved whereby the feed is more easily and accurately reset and controlled.

A further object has been to provide an im proved drill spindle assembly sustained in an improved bearing arrangement, whereby the correct axial alignment of the spindle and true running of the drill are maintained. For this pur- I pose, the-transmission connection for transmit-v ting the drive to the spindle is disposed approximately in the plane "of the lower bearing. In this improved construction; the main driving gear, particularly for low speeds. is journaled' independently of the spindle assembly so that those driving stresses on the teeth of this gear, which normally tend to 'disalign the spindle, are not con-v veyedto the spindle. Speciflcally,'the drive gear is journaled concentrically with the spindle upon aheavy bearing sustained by the head. Therefore; the head receives the heavy driving stresses.

Another object has been to provide a. radial drill-head in which the various parts of the feed transmission and control and tripping mechanism assembly are readily accessible for replacement or repairs. In order facilitate the assembly of the parts within the head, the feed gears, the shifting means and the tripping means of the feeding mechanism are assembled in a single bracket, which is removable bodily from the head.

Other improvements are disclosed as to the connections between the shifting levers and the gears wherein these parts are more compactly arranged and assembled, and wherein the shift of groups of gears in each transmission, that is, speed and feed, is accomplished through cams and shifting movement of the gears in the proper sequence and order is insured.

Other objects and certain advantages of the invention will be more fully apparent-from the description of the accompanying drawings in which:

Figural is a front view of a radial drill, incorporating the present invention.

Figure 2 is a rear view of the radial drill with v the base broken away.

Figure 3 is a. top plan view of the radial drill.

Figure 4 is a sectional view taken on line 9-4, Figure 1, illustrating the driving and feeding means for the spindle.

Figure 5 is a top plan view of the rear trans-' mission casing of the head with the cover removed.

Figure 6 is a sectional view taken on line 6-5, Figure 5, illustrating the transmission extending from the drive shaft toward the base of the head.

Figure 7 is a sectional view taken on line 7-1, Figure 6, further illustrating the transmission.

Figure 8 is a sectional view taken on line 8-8, Figure 6.

Figure 9 is a sectional view taken on line 9-8, Figure 4, showing a portion of the speed gear shifting means.

Figure 10 is a sectional view taken on line Ill-l0, Figure 9, showing the means for rotating one of the shifting cams.

Figure 11 is a view illustrating a development of one of the speed gear shifting cams.

Figure 12 is a view illustratinga development of the other of the speed gear shifting cams.

Figure 13 is a sectional view taken on line l3-l3, Figure 4, showing the gearing at the base of the head.

Figure 14 is a sectional view taken on the line l-i-H, Figure 13, showing part of the speed gear shifting apparatus.

Figure 15 is an enlarged fragmentary front view of a portion of the head showing the dial and levers for spindle speed changes.

Figure 16 is a sectional view taken on line "5-! 6, Figure 15, showing the connection of shifting levers to the shifting means.

Figure 17 is a sectional view taken on line ll-l'l, Figure 16, further showing the shifting connections.

Figure 18 is a sectional viewtaken'on line l8-l8, Figure 17.

Figure 19 is a sectional view taken on line 'IB-IS, Figure 17.

Figure 24 is a sectionaliview taken online 28-24, Figure 22, showing additional details of the shifting mechanism.

Figure 25 is a fragmentary sectional view taken similarly to Figure 22, but showing one of the shifts diagrammatically.

Figure 26 is a diagrammatic view of the feed speed shifting means. Y

Figure 27 is a sectional view showing the telescoping arrangement of the shifting rods of Figure 26.

Figure 28 is a sectional view taken on line 28-28, Figure 22, showing the shifting cam in plan view.

Figure 29 shows a development of the cam tracks of the cam of Figure 22.

Figure 30 is a front view of the head, with the cover removed and portions broken away for illustrating the details of the feed mechanism for the spindle.

Figure 31 is a fragmentary front view showing a portion of the head illustrating the feed control dial and levers.

Figure 32 is a sectional view taken on line 32-32, Figure 30.

Figure 33 is a sectional view taken on line 33-33, Figure 30.

Figure 34 is a sectional view taken on line 34-34, Figure 30, illustrating more of the details of the head, including the spindle counterweight and the main feed control levers.

The general construction of the radial drill, in which the present improvements are disclosed, is as follows: A base .50 has a stump 5| rising from one end thereof. A column 52 is rotatably mounted on the stump and has a cap 53 attached to its upper end. An arm 54 is vertically slidably mounted on the column 52. This arm may be raised or lowered so as to place the arm in the proper position for locating the drill at the proper height, relative to the work. The work is mounted on the base 50. The arm is supported and elevated by means of a screw 55 depending from the cap 53 of the column.

A drill head 56 is slidably mounted for longitudinal movement on the arm 54, which projects radially from the column. For this purpose, the arm is provided with a rail 51 along its front face. A driven pinion 58- (Figure 4) engages a rack 59 fixed along the rear face of the rail. This pinion is rotated either by power or by hand through means disclosed and claimed in a, copending application, Serial No. 291,110, filed August 21, 1939, now Patent No. 2,295,516, issued September 8, 1942. The power for the drill is derived from an electric motor 60, mounted on the short end of the arm. The power is first directed through a shaft 6| into a gear box 62, containing arm elevating gearing and its control means, disclosed and claimed in a co-pending application. From the shaft 6|, the power is carried without break to a splined shaft 63, which traverses the drill head and is supported at its outer end in a bracket 64 on the outer end of the arm. Within the drill head the power is taken from the shaft 63 through reversing clutches 65-65 (Figure 6) directly controlled by means of a main power control lever 62 for the drill head.

From the reversing clutches 5-55, the power is delivered to the spindle 61 through speed control gearing. The shifting of this gearing for change of speed is accomplished by means of lever operated cams 8|, 2. The system provides for thirty-two speeds. A lever I. (Fig. 15) provides for shift alternatelyto high and low ranges.

as indicated on a dial I9.

Levers II-'-I2, movable with respect to a dial plate 13, shift the camfor shifting the appropriate gears in the selected ranges, as explained hereinafter.

From the spindle the drive proceeds through sixteen feed changes, is controlled for these changes by means of levers 16-11 at the face of the head (Figure 31) The upper of these levers effects shift from low to high range, or vice versa. The lower lever 11, through a cam I8 (Fig. 22), accomplishes the changes in the respective ranges,

The amount of feed is controlled by means of a setting-and indicator dial 80. The feed connection is controlled manually by means of levers 3I-8I (Fig. 1), and automatically, by means of a dog 82 (Fig. 30). Dogs 83-83 on the variable counterbalance additionally control the spindle feed, keeping it within normal limits by automatically stopping the feed, regardless of the hand setting of the feed dial. A hand wheel 8d provides for manual feed. A lever 85 couples either the-hand wheel or the power feed.

Power traverse of the head is controlled by means of a lever 86. A hand wheel 81 is provided for traversing'the head by hand. A lever 80 operates the head cla-mp. Lever 39 controls the clamp ing of the arm to the column and the elevation of the arm. The column is clamped by means of an electric motor 90 on the arm. This motor is controlled by means of clamp and unclamp push buttons 9I-3I on the head just below the speed indicator dial. Separate applications are co-pending, namely, Serial No. 297,722, filed Oct. 3, 1939 and Serial No. 291,110, filed August 21, 1939, now being respectively Patents Nos. 2,278,262, issued March 31, 1942, and 2,295,516, issued September 8, 1942, directed to the variable counterbalance mechanism shown in Figures 30 and 34, and the head traversing mechanism and other features of the radial drill disclosed herein.

The power to the head The main -electric motor 60 is bolted on the short extension of the arm. Its shaft 92 carries a coupling element 33 which is coupled with the extended arm of a power shaft bolted in gear box 02. The gearbox at the other side thereof has a driving shaft 63 extending therefrom into connection with the head. Within the gear box 62' suitable elevating mechanism is employed, but since the elevating mechanism forms no part of the present invention, its details are not disclosed herein.

The head 56 includes a rear casing section I03 (Fig. 4) which houses the reversing gearing for the spindle, and part of the spindle driving transmission. The head generally described is of the conventional form, (Figure 4) that is to say, includes the rear casing I03, a front casing I04 in which the drill spindle is vertically disposed, and a lower transmission casing or extension I05 of the front casing. connecting the front and rear casings. The arm passes through the space thus provided between the front and rear casings. The rear face of the front casing includes the guide grooves and supporting means which engage u on a the rail of the arm.

have circular flanges I09 secured to the ends of the casing I03 by means of screws H0. The assembly of the sleeve in the bearings is maintained by means of washers IIi, engaging the clutches against shoulders on the sleeve at the inner side of each clutch, and nuts II2 screwed on the ends of the sleeve and fastening the inner races of the bearings against the washers. The bearing brackets include felt packing rings I I3 surrounding and sealing the ends of the sleeve. One of the brackets includes a removable bushing IIfi, providing access to one of the nuts H2, so as to permit removal of the nut I I2 and withdrawal of the sleeve through the other end of the casing.

Reversing driving gears I I5-I I5 are loosely rotatively mounted on the sleeve I06 toward the respective ends thereof. These gears in each instance are journaled on spaced bearings I I5I I6, fixed on the driving sleeve. Within each gear is a clutch 85. An element I I! of each clutch is keyed to the driving sleeve between the spaced bearings lie-H6. This element supports a clutch ring H2, carrying a clutch band IIB.

Since the clutches form no part of the invention described and claimed in this application, it is believed unnecessary to show and describe the clutch details. Generally described, a clutch actuating key I20, mounted in a keyway in the sleeve between the clutches, alternately actuates the clutches for connecting the gears to the splined shaft. This key I20 has feathered ends engaging under the ends of respective levers I2I. These levers, when rocked, spread the clutch bands and cause them to grip the internal periphery of the gears. A yoke ring I22 encircles the sleeve and key centrally of the clutches and is fixed to the key so as to slide the key longitudinally when actuated. A yoke I23 (Fig. 7) engages in an annular groove in the yoke ring.

The yoke I23 is fixed on a shifter rod I24 by means of screws I25. The rod is slidably mounted in lugs I28 of the casing; A lever arm I21, bolted to the upper end of a vertical rod I28, has a ball and socket connection with one end of the shaft I 24. The vertical rod I28 is journaled for rotation in an upper lug I29 and a boss I30 in the base wall of the casing. The long main con trol lever 08 (Fig. 13) is fixed to the extended lower end of the shaft I28 and has its knob end extended out to the front of the head just below the spindle speed shifter lever assembly. Accordingly, horizontal movement of the lever 66 controls the delivery and direction of power entering the drill head.

A reversing idler gear I3I is provided in mesh with one of the gears H5. This gear (Figs. 6, 7 and 8) is journaled on a short shaft I32 between spaced bearings of the casing. The power is transmitted from gear IIS through this gear, for the drill return operation, to gear I33, fixed on the splined shaft I34. For the feed and rotation of the drill in boring, a slow speed is obtained through the other gear IIS, meshing directly with a large gear I35, fixed to the shaft I34.

The lubricant pump I36 for the head is fixed to a cover. plate I31 in an opening in the back of the head. The pump shaft I38 (Fig. 5) extends into a driving sleeve I39, Journalled in bearings I40 in spaced lugs I4I of the cover plate I31. The slegye I39 includes a gear I42 meshing with driving gear I43, keyed to the driving sleeve I06. The pump has an intake conduit I44 extending up from the sump of the head casing, and an outlet tube I43 extending over-to a filter I46, also fixed to the cover plate I31.- Lubrication lines I41 extend from the filter to the various bearings of the head. Thus, all of the elements of the lubrication system are secured to the cover plate I31 and may bequickly removed as a unit.

Spindle drive As stated, the gears I33 and I35 transmit rapid drill return movement and slower power or drilling movement respectively, as controlled by the main lever 56. They are fixed to the same shaft, namely, I34. Four speed changes are obtained in the upper ,or rear casing I03, and these four are stepped up to thirty-two speeds (20 R. P. M. 1600 R. P. M.) in the lower casing of the head at the connection to the spindle.

In addition to gears I33 and I35, three other gears, namely I50, II, and I52, large to small, are-fixed to the splined shaft I34. These gears I33, I35, I50, I5I, and I52 are held in a cluster on the shaft. End bearings I53 support the shaft I34 in the end wall and-a central wall of the casing.

The shaft I34 includes an extension I54 between the central wall and the other end' wall. This extension journals a gear I55, meshing with the gear I43 and forming part of the head traversing gear train, described and claimed in the co-pending application Serial No. 291,110, filed August 21, 1939, now Patent No. 2,295,516, issued September 8, 1942.

Just below shaft 134 another shaft I56 is rotatably supported in bearings I51--I51 in the end wall and central wall of the casing parallel with the shaft I 34. This shaft is splined and carries shiftable gears I58, I59, I60 and IGI component to the gears I33, I50, I5I. and I52. These gears are in independently shiftable sets of two gears each. In each instance one gear includes a hub I62, upon whichthe other gear ofthe set is held by means of a nut I63. The last named gears include annular grooves I54. These grooves I64 are engaged by shifter yokes I65, I05 (Figure 9). The yokes are slidably mounted on a rod I61 and are actuated by means of the cam 68. Each yoke includes a roller I68 engaged in 'a particular cam track, the arrangement of which is illustrated in Figure 12. I

A bevel gear I59 is fixed to the shaft I56 and meshes with another bevel gear I10, fixed to the upper end of a'vertical shaft I1I. Shaft IN is journaled in bearings I12-I12 in the upper and lowerwalls of the lower casing I08 (Figure .4); The gear I is journaled directly in the upper bearing. A shiftable gear cluster consisting of gears I13, I14 is slidably mounted on the splined portion of shaft "I. The gears are held together ported on one end of a pivoted lever I80. The

yoke is slidably mounted on a fixed vertical rod permits easy shifting. The yoke carries theball bearing I18 of the cluster and provides a connection in which thegear cluster may rotate and upon which the gear clusteris supported.

Another vertical shaft I89 is journaled in bearings I90-I90 in the. upper and lower walls of the lower casing. The lower bearings are accessible by removal of a cover plate I9I fixed on the base wall of the casing over an opening therein. A shiftable cluster of three gears I92, I93 and I94 is slidably mounted on the splined portion of the shaft I89. A yoke I95 provides for shifting,

of this cluster and is slidably mounted on a vertical shaft I96. The ball bearing I91 carried by the yoke for permitting rotation of the gears is fixed between gears I92 and I93 and these elements are held on the hub of and against gear I84 by means of a nut I98.

A lever I99 is pivoted on a pin 200 on the lug I84 and has a roller 20I at one end engaging a cross-slotted portion of the yoke I95. The other end of the lever carries a. roller 202 engaging a cam track of the cam 59. A coil spring 203 under tension between a pin 204 on the lug I84 and the pin 205 carrying the roller 202 is effective for counterbalancing the weight of the gear cluster, the yoke, and the lever. "Due to these springs I85 and 203, there is very little resistance to overcome in the operation of rotating the cam and shifting the levers.

Another vertical shaft, namely, 209 (Figure 4) is journaled in upper and lower bearings 201-201 fixed in the upper and lower'wall of the lower casing. The lower bearing is accessible through cover plate I 9I. This shaft has three gears, namely, 208, 209 and 2I0 fixed thereto. These gears are not shiftable. Thesmall gear 2I0 is in constant mesh with a bull gear 2 loosely jour- I8I and provides a cross-slotted portion engaged r by the roller I82 onthe endo! the lever. The

pivot pin I83 for the lever is mounted in e108 I84 of the casing. The other end of the lever carries a roller I85 engaged in a track oi'the cam 69. coil spring I85 disposed under pressure between a pin I81 on the lug I84 and the pin I88. carrying the roller I82, counterbalances the naled on a double roller bearing 2I2 on the axis of and around the lower end of the spindle.

A driving sleeve 2| 3 for the spindle is supported and journaled in an'upper roller bearing 2 in a lug of the casing and a roller bearing 2I5 adjacent the bearing 2I2. The spindle is in splined connection within this sleeve 2I3 by means'of keys 2I5 and provides the conventional chuck for reception of the drill.

A cluster of two gears 2 I1 and 218, is in splined connection with the driving sleeve 2I3 and is shifted by means of a yoke 2I9. These gears are integral and provide a sleeve portion having an annular groove 220. The yoke 2I9 engages the groove. The gear 2I8 is adapted to couple with the internal gear of the bull gear and the other, namely, 2I1, with the gear 208 for coupling either of these gears with the spindle.

Speed shift means The yoke 219 includes a vertical lug portion 222 bolted to a vertical shift rod 228 slidably mounted in plain bearing lugs 224224 in the casing (Figure 14). A bell crank 225 is pivotally mounted one. pivot pin 225. This bell crank carries a roller 221 adjacent ,the end of one arm. This roller engages a cross notch in theof the casing or box 228. The inner end. of the shaft carries a lever arm 23I having a pin 282 weight-of the lever. the yoke. 8nd the year and 7 enga ing a r s roove inthe rod 228.

. "The cam 60 (Figure the shaft NSJ -The-sIeeve has for vertical movement as .lever passing through. the plate.

lever and on assmaa A coil spring 233, under-tension between a pin 23 on the end of the yoke supporting arm of thebell crank and a pin 235 on the casin ...untel-balances the gear cluster, the yoke. and the rod, and takes the weight of these parts off the shifting means for the purposes described here tofore. Thus this gear cluster 2I1-2I8 has two positions accomplished by shifting the lever alternately to low orhigh speed range (Figure The cam" is rotatably mounted,;being fixed to a shaft 235 journaled in bearings 231-231. A gear 238 is fixed on one end of theshaft and is in mesh with a gear a stub shaft 200 fixed in gear 230 is in tached to a shaft 242 extending across the casing thecasingwall. .This

- and johrnaled' in bearings 243-243 in its side.

walls. An arm 24411; axed to the shaftat the end opposite the ear segment and is connected by a link (a to a shifter am 245 rotatively (Figure 16). This arm .ball bearings .on .the shaft 246 and carries the shifting lever 1I screwed into its forward side.

9) is fixed on a shaft vertically ball bearlnsll'I-ZQI. in the upper and lower walls of the casing. A-gear 248 shaft at its lower end and meshes with 'a gear segment "209 (Figure 13.). .Iour-v naled' about the; shaft I20 and includes an arm I is attached. Theother to-an'arm 2 52 (Figure 16). -"This'arm252 is dournaledion a shaft 253 on ;254- -25'4 randaincludes a segment of bevel teeth"255jmeshing'with; a .bevel gear 258 tnlo'untedbn and tired to-asleeve 251 239 (Figure 10) mounted on.

mesh witha gear segment-2M 'at-.

' made' from 20 R. P.

" mounted on ashaft 246 journaled in the box 229 245 is journaled'on spaced fspindle drive pointing angularly upwardly in parallelism with thelines 285.

As the levers are set in the drawings. Figure 15, the speed of 20 R.'P. M. is indicated since 20 R. P. M. is the only panel section toward which both arrows are pointed. The operator reads the white panels for the reason that the lever 10 is set in the low range of speeds. The operator may very quickly shift the spindle speed from 20 R. P. M. to 193 R. P. M., that is change'from one range to the other by moving the lever 10 to. the right into the high speed zone. driven at 193 R. P. M. i..e., the arrows of the shifterlevers. H and 12 both point to the black areas indicating 193 R. P. M. Assuming the lever 10 to be in the low speed range. a shift can be M. to 31 3.1. M. by movin the lever 1| downwardly into alignment with the v last inclined row of areas at which point its arrow .will point at 3|. Also. as anotheriexample, the

operator may shift from 20 R. P. M. to 109 R. P.

M. by moving the right-hand lever 12 into alignment with its last inclined row of areas whereupon both arrows will point'at 109 in this row.

As may be evident from the speed panel,- thirtytwo speeds are possible. ered to shaft I56 through the four sets of gears. Thus, shaft I1I receives'four speeds. shaft I83 eight speeds, shaft 206 sixteen speeds, and the sleeve thirty-two speeds. Three positions are provided. at shaft m (Figure 4),

gear I93, gear I13 may journaled"on' 'spaced"b'all bearings 258-458on 12 projecting radially therefrom. v

The levers 1I :"and 12 project throughrespec tive vertical slots 259-259 in the face of the casing (Figure 15). Theseslots are spaced apart. The indicator plate 13 is fixed on, the face ofthe casing and has shifting indicia disposed between the slots. Each slot includes a tionin which a sliding cover plate carried by the shifting .The plate 13 carries all of the spindle indiciar The low speeds are indicated by enclosed white areas and the high speeds by enthe lever gear I13 maybe countersunk por- 260 is dispo set as indicated and For indicating the'l-speeds-of the respective ranges. the indlcia consists of a series of lines 285 drawn'upwardly from These lines cross ea'ehother. to form a serles of the inner edges of the slots.

diamond-shapedareas 266. These areas are divided into equilateral triangles by vertical lines 261. Those portions of the diamond-shaped areas on the right-hand side are black and those on the left-hand side are white. Both ranges of speeds read from left to right down each inclined row of diamond-shaped panels. .Just below each the cover plates 260 230 gears may be since the gears I13 and I1l'may the gears I02,and I 03 or these respective sets of with gear 200 and geari I14 with be shifted to mesh'with' gear I92. Thus the speeds available at shaft'200 through gear 200 are eight. when'gear 194.15 in mesh with gear 208 and shifted one notch higher l92 is meshing to mesh again with-868,1 at shaft 206 through gear 200 are eight making a totalcf'sixteen gear M0 to the bull gear 2 to the spindle, or

through gear 208 through gear 2" to the spindle for a total of thirty-two speeds.

, The drawings show the system effective for de-- livering the lowest speed to the spindle,

namely 20 R. P. M. (see Figure 15). To produce the mesh of gears necessary for this speed, the levers are the cams rotated so as'to shift gears into the following meshing arrangement. The upper earn 58. "(shifts gear IBI into mesh with gear I52 leaving the other cluster-of gears I59, I60 in'neutral (Figure 8). Gear I84 is engaged with gear 208 (Flam 4) by means o'f-the lower-cam 69 through lever I00 actuated by shift lever 12. Lever 12, also through the lower cam. actuates gear I13 to cause it to mesh with gear I92. Lever 10 has moved ear 2|! intg coupling enga ement with the internal gear of behaved necessary to -Thoperatormaylumpthespeedfrom20 R. P.M.to1600R-.1 '.1Lifdesired. Inthisevent. rotation of th upper cam .08 shifts the gear-I58 into meshwithth'e gear I33 (Figured) andmai'n tains the other cluster of gears I53, I00 in neutral. The other-cam 69 is effective formoving I82Linto mesh with gear 200 and gear I14 into m l fi th 8681' "3 (Flame 4). At thesame time. the range control lever .10 has been moved to'the h The spindle will then be- .Four speeds are delivmove either with moved independently. when gear.

gear I03 with=gear'l1l,

I92.- Thus thespeeds available speeds either passing through actuated by shift lever the bull gear. It isnot trace out each of thesewhlch imcouples the bull mmw-- gear from the spindle and. connects the spindle through gears 208 and 2H. I

Now, each of the shift levers In. H. and I2 are provided with detent means for accurate y estabo-lishing the various positions; Lever (Q has only sleeve 15, the teeth of which are in mesh with the feed gear 14.

The feed transmission gear change unit. Figure 21, is supported in a bracket 352. attached to the 5 back wall of the main head casingand is accurately positioned for driving engagement with the gear 350 when secured. As stated heretofore. this transmission develops sixteen feed changes Three spllned shafts are employed, namely 353,

1 354; and 35S. Each is journaled vertically in tween the roller carrying endfofthe. annanda stud 215' fixed 'to the casing. Thus, the roller 1 may snap into either one of the grooves for deflnitely fixing the-predetermined position i of the lever 10.

The lever 12 provides four each or which is d pted to place the transmission in four different speeds dependent upon the position of the other lever H which also has four positions. i

' For this purpose. the gear (Figure 181 actuated by the lever 12 includes a, flange 216 providing tions in all fandithese-sixteen i'ng leakage of oil from-the easing lug 85!. Figure 21.

four detent grooves or notches 211-. .A bell crank :18 is pivotally'. mounted'ln'the'casing on a pivot 25 pin :19. 'One a m-2st of this b'ell crank carries a roller engaging the notches successively and the other has its end connectedto a mg 12 of the .i'.hegroov es.-- The other lever-"ll has its operating -videdwith a serles'of four-notch" W detent 'nieans e: :the same "tbs-Fins;

. casing bymeans of-a coil sprlngjunnderfltenebearings 356 at the top and bottom fixed in upper and lower extensions of the bracket 352 and held in position by means of nuts 358 and'the plate 351 at their upper ends.

The first shaft 353 has the gear 359 fixed to it:

lower end below a flange of the bracket and sustained by means of a collar 360. Two slidabh gear clusters are provided on this shaft 353 con sisting of gears 38!, 362 and gears 363, 36

respectively. The second shaft, namely 354 ha two gear clusters fixed thereto. One consists o gears 365 and 366 component to gears 36! and 361 and the other, gears 361. 368. component to gear 363 and 384;

Gears JGS-and 364 are shifted to-either of tw positions by means or a yoke 369. Figure 2f engaging inan annular groove in the gear cluste and-fixed to ashiit rod m.- Gears 36! and 38 areshifted by means of the yoke 31 I engaging i ve in the gear cluster and flxedt the tubular-shlftrod 312 in which rod-31o ls tel rsccpicallyengaged. Thus {our speeds may i:

-..:impartcdtoshaftlfl. a

*1 'lhe thirdeshaft. namely 355. has a gear c1ust r Thins-th two lever I and-Hin fixed thereto consisting or gears .31: and :14.

di 'e fo r positions oie'eeitoovidei'sisteen'podgear cluster consisting-of gears as and as, con

doubled'by means of the lev v The'casing. which carries the-levers Add r dons are "ponent'to gearsjll-and m, is slidably mount:

.-"on ghaftlil. This gear cluster is shifted! means of a yoke ill. Figures 22 and 25, fixed also carries wheel U f r 119314 f shift rod 818.; Shaft 355 is journaled-ina lug 3 switches 9|, SI for the column clamp" The driving sleeve 2|! for the spindle'is-iour- Ila-16d 1 h pper-roller bear g!" "inthe 1 8, extreme lower end of the shaft 355 is journaled top of-the shaft and the bearing in lug :19. T1

of the 8 and h roller bearing"! (5 adjacent. 5 a bearing 38! in a lug 382- near the lower end -the doublebearlng 212.- The spindle 61 is in splined connection within this sleeve by means of keys 2 l6 and provides the conventional chuck for reception of the drill. The double bearing.2i2 is the bracket .352.

A gear383 is loosely rotatably mounted 4 the shaft 355 just below the gear clusters 31 314. This gear includes a heavy hub and is su supported on theboss 288 r the lower wait or the so ported on a double ball bearing 384, the inn casing and held there by means of a collar 28! engaging the top of the bearing. This collar.281

- race of which is fixed between a shoulder on t shaft and a'sleeve 38$ engaged against the low s w d n a s e ve 8 dispos d hithe boss end of the gear clusters .313, 314.

and has a headed lower-end seated in: a counter "Just below the gear'383. agear 386 is slidal sinkin a cover plate 289 which encircles the lower mounted on the splined portion of the shaft -3 end of the driving sleeve. A ring 230 is secured by bolts ZBI to the under side of-the gear and holds the gear -on the. hearing." The driving sleeve rests on the bearlng through a shoulder.

' ,This gear is shifted from one feed range to a other by means of the lever 18 disposed at t front of the head for this purpose. A yoke 8 fixed on a slide rod 888,- Ffigure 24, engages A nut 292 on the sleeve engages the bearing '60 an annular groove in this gear 188 and is op ,against the shoulder and secures the pacldng 19} lnplace. Additionalpackimshowng'enerailyat.

,284, seals the spindle driving means {or revent.-

Thegear 3834s in constant mesh with a El 389 or the gear cluster 880, 890. This in cluster'is rotatably-mounted on a shaft 831 h:

oiinzitsm rendloumaledintheballbean :32 man extension of the bracket 852 and .lower end-journaied in azball-bearinc 8,9! in lowerwallotthebracket. Thlsshoit lsin a: alignment withthe shaft 384.- A ahlitableg i sirom'age rfimflxedtothealeevebetwem a 10 8941s mounted-onthe-shait 3" and is in c shoulder-of the sleeve and the bearing 2. I cured in a circular-recess inthe underside'of the The upper end of the spindlels conntertnmed and once-8 mesh with a gear SIS. W 395 is fixed-to I. shaft 8 16mm and lower bearings! in the bracl 1Aeworm-fl8 is fixed tojthe shalt between rotatively witbinthev 'molidablonon-rotatablemkto 

